Hot and Sour Soup is a popular Chinese soup that is both spicy and tangy. The soup is made from a combination of ingredients like mushrooms, tofu, bamboo shoots, and eggs, which are cooked in a flavorful broth made from vinegar, soy sauce, and chili paste. The soup gets its spiciness from the chili paste and its tanginess from the vinegar. It is a comforting and satisfying soup that is perfect for a cold winter night.